Then just take the slot grid, cross over all slots 11 or higher, and cross over any extra slots for spells already cast that day (mage armor). If you don’t want to mess up the sheet, use hash marks on a separate scratch paper, place beads, make a wooden pegboard, anything – the point is to instantly get an overview of the slots available for a particular level.

Beside each row, I’m going to put a selection of spells for that row in precedence order. For example, the third row will have “Fly, Counterspell, Lightning Bolt” and they will be overwritten from left to right, so if the prep says that this particular wizard favors Fear, then Fly will be overwritten and she’ll be able to cast “Fear, Counterspell, Lightning Bolt”.